With such warning apparatuses, it is desirable for warnings about the objects detected by the sensor device to be given only if this is also actually appropriate in view of the driving situation, because otherwise unnecessarily frequent generation of warning signals means that the driver's acceptance of the apparatus is reduced.
An apparatus of the type in question is discussed in DE 10 2009 041 555 A1, for example. This document describes dynamic range limiting for the detection area for a turning assist system and a blind spot assist system. In particular, it describes a lateral and rectangular warning area that is dynamically alterable on the basis of the speed of the vehicle as seen in a direction perpendicular to a vehicle side. The dynamic lateral warning area extends between a non-zero lateral minimum distance (0.4 meter) and a maximum distance (2.5 meters) from the vehicle. When the vehicle turns, a future travel corridor and a tractrix of the vehicle are estimated. A warning signal about stationary objects is generated only if a stationary object is in the travel corridor, including the tractrix, of the vehicle. The document does not specifically reveal how the travel corridor, including the tractrix, of the vehicle are estimated.